Orange Pi PC 2 - network booting - Try the Pine64 scheme on my PC 2

I obtained my boot0.img file from one of the functioning Ubuntu SD cards I have by doing:

dd if=/dev/sd of=boot0.bin bs=8k skip=1 count=4

I am trying to use the 2017.05 U-Boot distribution. This builds for the PC2 in the usual way, but does not yield an SPL. The only clue about what to do with the image it builds is in the file u-boot-2017.05/board/sunxi/README.pine64). I tried using this scheme, and it fails (see the console messages below). Searching on the error messages (which come from boot0.img) led me to this highly relevant discussion on the U-Boot list:

• April 2017 discussion

The H5 boot0 changed quite a lot, so the A64 runes don't work anymore. The way the different meta data of the firmware parts (ATF, U-Boot, arisc) are stored is different. I really couldn't be bothered to rev-eng and hack this dead end (again). And since we have the SPL code working already this time, I thought we just go with the proper stuff.

HELLO! BOOT0 is starting!
boot0 commit : 8
boot0 version : 4.0
set pll start
set pll end
rtc[0] value = 0x00000000
rtc[1] value = 0x00000000
rtc[2] value = 0x00000000
rtc[3] value = 0x00000000
rtc[4] value = 0x00000000
rtc[5] value = 0x00000000
DRAM BOOT DRIVE INFO: V0.6
the chip id is 0x00000001
the chip id is 0x00000001
the chip id is 0x00000001
the chip id is 0x00000001
the chip id is 0x00000001
axp not exist
DRAM CLK =672 MHZ
DRAM Type =3 (2:DDR2,3:DDR3,6:LPDDR2,7:LPDDR3)
DRAM zq value: 0x003b3bf9
DRAM SIZE =1024 M
DRAM simple test OK.
dram size =1024
card no is 0
sdcard 0 line count 4
[mmc]: mmc driver ver 2016-03-15 20:40
[mmc]: sdc0 spd mode error, 2
[mmc]: Wrong media type 0x00000000
[mmc]: ***Try SD card 0***
[mmc]: HSSDR52/SDR25 4 bit
[mmc]: 50000000 Hz
[mmc]: 15193 MB
[mmc]: ***SD/MMC 0 init OK!!!***
PANIC : sunxi_flash_init() error --2--,toc1 magic error
PANIC : sunxi_flash_init() error --2--,toc1 magic error
PANIC : sunxi_flash_init() error --0--
Ready to disable icache.